Novel potassium-boron metal-organic frameworks: Influence of ligand variation on structural and hydrogen storage properties

In this study, two novel potassium-based metal-organic frameworks (MOFs) mediated by boric acid were synthesized via a one-pot self-assembly reaction using terephthalic acid and acetylenedicarboxylic acid as ligands in ethyl acetate. The synthesized compounds were thoroughly characterized using Fourier-transform infrared spectroscopy (FT-IR), powder X-ray diffraction (p-XRD), thermogravimetric analysis (TGA), elemental analysis, and single-crystal X-ray diffraction (sc-XRD). Structural analysis revealed the molecular formulas of the new compounds as C16H18B2K4O16 and C2H3BKO5, respectively. Both compounds exhibited high thermal stability. The Brunauer-Emmett-Teller (BET) surface area measurements indicated values of 2.152 m2/g for the potassium terephthalate-boron complex and 4.468 m2/g for the potassium acetylenedicarboxylate-boron complex. Variations in the ligands influenced the surface area, pore volume, and pore size of the complexes, which, in turn, affected their hydrogen storage capabilities.